Reducing digital image noise

An apparatus, comprising:

• mosquito noise detection logic configured to detect an amount of mosquito noise present in a digital image;
• block noise detection logic configured to detect an amount of block noise present in the digital image;
• filter logic configured to filter the digital image to produce at least one of, a 2-dimensional (2D) mosquito filter output, a 2D block filter output, a 1-dimensional (1D) horizontal block filter output, and a 1D vertical block filter output;
• selection logic configured to select, based, at least in part, on the amount of mosquito noise and the amount of block noise a correction filter output to improve image quality, the correction filter output being a combination of the 2D mosquito filter output, and the 2D block filter output when the digital image is determined to be blocky across the digital image based on the amount of block noise, and the correction filter output being a combination of the 1D horizontal filter output, and the 1D vertical filter output when the digital image is determined to not be blocky across the digital image based on the amount of block noise;
• and
• compression artifact logic configured to reduce a compression artifact in the digital image based, at least in part, on the correction filter output.

An apparatus comprising:

• mosquito noise detection logic configured to detect an amount of mosquito noise present in a digital image;
• block noise detection logic configured to detect an amount of block noise present in the digital image;
• filter logic configured to filter the digital image to produce at least one of, a 2-dimensional (2D) mosquito filter output, a 2D block filter output, a 1-dimensional (1D) horizontal block filter output, and a 1D vertical block filter output;
• selection logic configured to select, based, at least in part, on the amount of mosquito noise and the amount of block noise a correction filter output to improve image quality, the correction filter output being at least one of, the 2D mosquito filter output, the 2D block filter output, the 1D horizontal filter output, and the 1D vertical filter output;
• and
• compression artifact logic configured to reduce a compression artifact in the digital image based, at least in part, on the correction filter output;
• where the block noise detection logic is configured to detect the amount of block noise present by:
• determining a horizontal block boundary based, at least in part, on one vertical column of pixels in the digital image;
• incrementing a horizontal accumulator corresponding to a phase of the horizontal block boundary;
• determining a vertical block boundary where the vertical block boundary is determined based, at least in part, on at least one horizontal row of pixels in the digital image;
• incrementing a vertical accumulator corresponding to a phase of the vertical block boundary;
• and
• generating a block grid of the digital image based, at least in part, on horizontal accumulator values and vertical accumulator values, where the block noise detection logic is configured to detect the amount of block noise based, at least in part, on the block grid, and pixels of the digital image.

A method, comprising:

• upon determining that mosquito noise is present in a digital image, generating a mosquito noise output, where the mosquito noise output indicates a mosquito noise magnitude;
• upon determining that block noise is present in the digital image, generating a block noise output, where the block noise output represents a magnitude of block noise, and where the block noise output identifies the block noise as being one of vertical block noise, horizontal block noise, and global block noise, wherein the global block noise is comprised of horizontal block noise and vertical block noise throughout the digital image;
• creating a 2-dimensional (2D) mosquito filter output, a 2D block filter output, a 1-dimensional (1D) horizontal filter output, and a 1D vertical filter output by filtering the digital image with at least one of, a 2D mosquito filter, a 2D block filter, a 1D horizontal filter, and a 1D vertical filter;
• selecting a correction filter output to improve image quality based, at least in part, on the mosquito noise output and the block noise output, the correction filter output being a combination of the 2D mosquito filter output and the 2D block filter output when the digital image is determined to be blocky across the digital image, and the correction filter output being a combination of the 1D horizontal filter output and the 1D vertical filter output when the digital image is determined to not be blocky across the digital image;
• and
• reducing a compression artifact in the digital image based, at least in part, on the correction filter output.